A Novel Tetramethylpyrazine Chalcone Hybrid- HCTMPPK, as a Potential Anti-Lung Cancer Agent by Downregulating MELK.

Purpose: Lung adenocarcinoma currently ranks the leading causes of cancer-related mortality worldwide. Many anti-inflammation herbs, like tetramethylpyrazine, have shown their anti-tumor potentials. Here, we evaluated the role of a novel chalcone derivative of tetramethylpyrazine ((E) -1- (E) -1- (2-hydroxy-5-chlorophenyl) -3- (3,5,6-trimethylpyrazin-2-yl) -2-propen-1, HCTMPPK) in lung adenocarcinoma. Methods: The effects of HCTMPPK on cell proliferation, apoptosis, and invasion were investigated by in-vitro assays, including CCK-8, colony formation assay, flow cytometry, transwell assay, and wound-healing assay. The therapeutic potential of HCTMPPK in vivo was evaluated in xenograft mice. To figure out the target molecules of HCTMPPK, a network pharmacology approach and molecular docking studies were employed, and subsequent experiments were conducted to confirm these candidate molecules. Results: HCTMPPK effectively suppressed the proliferative activity and migration, as well as enhanced the apoptosis of A549 cells in a concentration-dependent manner. Consistent with this, tumor growth was inhibited by HCTMPPK significantly in vivo. Regarding the mechanisms, HCTMPPK down-regulated Bcl-2 and MMP-9 and up-regulating Bax and cleaved-caspase-3. Subsequently, we identified 601 overlapping DEGs from LUAD patients in TCGA and GEO database. Then, 15 hub genes were identified by PPI network and CytoHubba. Finally, MELK was verified to be the HCTMPPK targeted site, through the molecular docking studies and validation experiments. Conclusion: Overall, our study indicates HCTMPPK as a potential MELK inhibitor and may be a promising candidate for the therapy of lung cancer.

The Synthesis of 2'-Hydroxychalcones under Ball Mill Conditions and Their Biological Activities.

Chalcones are polyphenols that belong to the flavonoids family, known for their broad pharmacological properties. They have thus attracted the attention of chemists for their obtention and potential activities. In our study, a library of compounds from 2'-hydroxychalcone's family was first synthesized. A one-step mechanochemical synthesis via Claisen-Schmidt condensation reaction under ball mill conditions was studied, first in a model reaction between a 5'-fluoro-2'-hydroxyacetophenone and 3,4-dimethoxybenzaldehyde. The reaction was optimized in terms of catalysts, ratio of reagents, reaction time, and influence of additives. Among all assays, we retained the best one, which gave the highest yield of 96% when operating in the presence of 1 + 1 eq. of substituted benzaldehyde and 2 eq. of KOH under two grinding cycles of 30 min. Thus, this protocol was adopted for the synthesis of the selected library of 2'-hydroxychalcones derivatives. The biological activities of 17 compounds were then assessed against Plasmodium falciparum, Leishmania donovani parasite development, as well as IGR-39 melanoma cell lines by inhibiting their viability and proliferation. Compounds 6 and 11 are the most potent against L. donovani, exhibiting IC50 values of 2.33 µM and 2.82 µM, respectively, better than the reference drug Miltefosine (3.66 µM). Compound 15 presented the most interesting antimalarial activity against the 3D7 strain, with IC50 = 3.21 µM. Finally, chalcone 12 gave the best result against IGR-39 melanoma cell lines, with an IC50 value of 12 µM better than the reference drug Dacarbazine (IC50 = 25 µM).

Quinazoline-chalcone hybrids as HDAC/EGFR dual inhibitors: Design, synthesis, mechanistic, and in-silico studies of potential anticancer activity against multiple myeloma.

Two new series of quinazoline-chalcone hybrids were designed, synthesized as histone deacetylase (HDAC)/epidermal growth factor receptor (EGFR) dual inhibitors, and screened in vitro against the NCI 60 human cancer cell line panel. The most potent derivative, compound 5e bearing a 3,4,5-trimethoxyphenyl chalcone moiety, showed the most effective growth inhibition value against the panel of NCI 60 human cancer cell lines. Thus, it was selected for further investigation for NCI 5 log doses. Interestingly, this trimethoxy-substituted analog inhibited the proliferation of Roswell Park Memorial Institute (RPMI)-8226 cells by 96%, at 10 µM with IC50 = 9.09 ± 0.34 µM and selectivity index = 7.19 against normal blood cells. To confirm the selectivity of this compound, it was evaluated against a panel of tyrosine kinase enzymes. Mechanistically, it successfully and selectively inhibited HDAC6, HDAC8, and EGFR with IC50 = 0.41 ± 0.015, 0.61 ± 0.027, and 0.09 ± 0.004 µM, respectively. Furthermore, the selected derivative induced apoptosis via the mitochondrial apoptotic pathway by raising the Bax/Bcl-2 ratio and activating caspases 3, 7, and 9. Also, the flow cytometry analysis of RPMI-8226 cells showed that the trimethoxy-substituted analog produced cell cycle arrest in the G1 and S phases at 55.82%. Finally, an in silico study was performed to explore the binding interaction of the most active compound within the zinc-containing binding site of HDAC6 and HDAC8.

Methoxychalcones as potential anticancer agents for colon cancer: Is membrane perturbing potency relevant?

Chalcones are naturally produced by many plants, and constitute precursors for the synthesis of flavons and flavanons. They were shown to possess antibacterial, antifungal, anti-cancer, and anti- inflammatory properties. The goal of the study was to assess the suitability of three synthetic methoxychalcones as potential anticancer agents. In a panel of colon cancer cell lines they were demonstrated to be cytotoxic, proapoptotic, causing cell cycle arrest, and increasing intracellular level of reactive oxygen species. Anticancer activity of the compounds was not diminished in the presence of stool extract containing microbial enzymes that could change the structure of chalcones. Moreover, methoxychalcones interacted strongly with model phosphatidylcholine membranes as detected by differential scanning calorimetry. Metohoxychalcones particularly affected the properties of lipid domains in giant unilamellar liposomes formed from raft-mimicking lipid composition. This may be of importance since many molecular targets for therapy of metastatic colon cancer are raft-associated receptors (e.g., receptor tyrosine kinases). The importance of membrane perturbing potency of methoxychalcones for their biological activity was additionally corroborated by the results obtained by molecular modelling.

Current scenario of chalcone hybrids with antibreast cancer therapeutic applications.

Breast cancer, an epithelial malignant tumor that occurs in the terminal ducts of the breast, is the most common female malignancy. Currently, approximately 70%-80% of breast cancer with early-stage, nonmetastatic disorder is curable, but the emergency of drug resistance often leads to treatment failure. Moreover, advanced breast cancer with distant organ metastases is incurable with the available therapeutics, creating an urgent demand to explore novel antibreast cancer agents. Chalcones, the precursors for flavonoids and isoflavonoids, exhibit promising activity against various breast cancer hallmarks, inclusive of proliferation, angiogenesis, invasion, metastasis, inflammation, stemness, and regulation of cancer epigenetics, representing useful scaffolds for the discovery of novel antibreast cancer chemotherapeutic candidates. In particular, chalcone hybrids could act on two or more different biological targets simultaneously with more efficacy, lower toxicity, and less susceptibility to resistance. Accordingly, there is a huge scope for application of chalcone hybrids to tackle the present difficulties in breast cancer therapy. This review outlines the chalcone hybrids with antibreast cancer potential developed from 2018. The structure-activity relationships as well as mechanisms of action are also discussed to shed light on the development of more effective and multitargeted chalcone candidates.

Chalcone derivatives disrupt cell membrane integrity of Saccharomyces cerevisiae cells and alter their biochemical composition.

Fungal infections can be serious or life threatening in severe cases, and the need to discover and find novel antifungal agents persists. Chalcones are plant-derived aromatic compounds that have been appealing synthons for pharmaceutical industry as they have good anticancer, antibacterial, antifungal and anti-inflammatory properties. Although there are few structure-activity relationship studies on chalcones, studies that link the structural features of these compounds to their mode of action are scant. Thus, in this study, we aim to clarify the relationship between chalcone derivatives and their cellular target within the yeast cell Saccharomyces cerevisiae. We observed that some chalcone compounds lead to disruption of cell membrane and cause ion leakage out of the cell. Moreover, chalcones alter the biochemical composition of yeast cells detectable by FTIR spectroscopy and bind to the DNA as shown by our titration experiments based on UV-Vis absorbance spectroscopy. Thus, their interaction with the DNA may be the major impact of these compounds on yeast cells.

Novel 3-(pyrazol-4-yl)-2-(1H-indole-3-carbonyl)acrylonitrile derivatives induce intrinsic and extrinsic apoptotic death mediated P53 in HCT116 colon carcinoma.

A novel series of α-cyano indolylchalcones was prepared, and their chemical structures were confirmed based on the different spectral data. Among them, compound 7f was observed to be the most effective bioactive chalcone with distinguished potency and selectivity against colorectal carcinoma (HCT116) with IC50 value (6.76 µg/mL) relative to the positive control (5 FU) (77.15 µg/mL). In a preliminary action study, the acrylonitrile chalcone 7f was found to enhance apoptotic action via different mechanisms like inhibition of some anti-apoptotic protein expression, regulation of some apoptotic proteins, production of caspases, and cell cycle arrest. All mechanisms suggested that compound 7f could act as a professional chemotherapeutic agent. Also, a molecular docking study was achieved on some selected proteins implicated in cancer (Caspase 9, XIAP, P53 mutant Y220C, and MDM2) which showed variable interactions with compound 7f with good Gibbs free energy scores.

Network Pharmacology Combined with Machine Learning to Reveal the Action Mechanism of Licochalcone Intervention in Liver Cancer.

There are reports indicating that licochalcones can inhibit the proliferation, migration, and invasion of cancer cells by promoting the expression of autophagy-related proteins, inhibiting the expression of cell cycle proteins and angiogenic factors, and regulating autophagy and apoptosis. This study aims to reveal the potential mechanisms of licochalcone A (LCA), licochalcone B (LCB), licochalcone C (LCC), licochalcone D (LCD), licochalcone E (LCE), licochalcone F (LCF), and licochalcone G (LCG) inhibition in liver cancer through computer-aided screening strategies. By using machine learning clustering analysis to search for other structurally similar components in licorice, quantitative calculations were conducted to collect the structural commonalities of these components related to liver cancer and to identify key residues involved in the interactions between small molecules and key target proteins. Our research results show that the seven licochalcones molecules interfere with the cancer signaling pathway via the NF-κB signaling pathway, PDL1 expression and PD1 checkpoint pathway in cancer, and others. Glypallichalcone, Echinatin, and 3,4,3',4'-Tetrahydroxy-2-methoxychalcone in licorice also have similar structures to the seven licochalcones, which may indicate their similar effects. We also identified the key residues (including ASN364, GLY365, TRP366, and TYR485) involved in the interactions between ten flavonoids and the key target protein (nitric oxide synthase 2). In summary, we provide valuable insights into the molecular mechanisms of the anticancer effects of licorice flavonoids, providing new ideas for the design of small molecules for liver cancer drugs.

Discovery of a new dihydroeugenol-chalcone hybrid with cytotoxic and anti-migratory potential: A dual-action hit for cancer therapeutics.

Cancer still represents a serious public health problem and one of the main problems related to the worsening of this disease is the ability of some tumors to develop metastasis. In this work, we synthesized a new series of chalcones and isoxazoles derived from eugenol and analogues as molecular hybrids and these compounds were evaluated against different tumor cell lines. This structural pattern was designed considering the cytotoxic potential already known for eugenol, chalcones and isoxazoles. Notably, chalcones 7, 9, 10, and 11 displayed significant activity (4.2-14.5 µM) against two cancer cell lines, surpassing the potency of the control drug doxorubicin. The reaction of chalcones with hydroxylamine hydrochloride provided the corresponding isoxazoles that were inactive against these cancer cells. The dihydroeugenol chalcone 7 showed the most promising results, demonstrating higher potency against HepG2 (CC50: 4.2 µM) and TOV-21G (CC50: 7.2 µM). Chalcone 7 was also three times less toxic than doxorubicin considering HepG2 cells, with a selectivity index greater than 11. Further investigations including clonogenic survival, cell cycle progression and cell migration assays confirmed the compelling antitumoral potential of chalcone 7, as it reduced long-term survival due to DNA fragmentation, inducing cell death and inhibiting HepG2 cells migration. Moreover, in silico studies involving docking and molecular dynamics revealed a consistent binding mode of chalcone 7 with metalloproteinases, particularly MMP-9, shedding light on its potential mechanism of action related to anti-migratory effects. These significant findings suggest the inclusion of compound 7 as a promising candidate for future studies in the field of cancer therapeutics.

Conarubins A-D: Four Monoterpene-Chalcone Conjugates from Conamomum rubidum and Their Anti-inflammatory and Cytotoxic Activities.

Four novel compounds, conarubins A-D (1-4), were isolated from the whole plants of Conamomum rubidum collected in Vietnam. Their structures were elucidated by extensive spectroscopic analyses and by quantum chemical calculations of NMR and ECD. Compounds 1 and 2 were the first examples of monoterpene-monoterpene-chalcone conjugates in nature, whereas compound 4 was an unprecedented monoterpene-substituted chalcone containing a 3,4,5-trioxygenated cyclohexa-2,5-diene-1-one ring. The anti-inflammatory and cytotoxic activities of all isolates were investigated.

2-Acetyl-5,8-dihydro-6-(4-methyl-3-pentenyl)-1,4-naphthohydroquinone-Derived Chalcones as Potential Anticancer Agents.

Based on previous results with benzoindazolequinone (BIZQ) and 3-methylnaphtho [2,3-d]isoxazole-4,9-quinone (NIQ) derivatives, a novel series of chalcone-1,4-naphthoquinone/benzohydroquinone (CNQ and CBHQ) compounds were synthesized from 2-acetyl-5,8-dihydro-6-(4-methyl-3-pentenyl)-1,4-naphthohydroquinone. Their structures were elucidated via spectroscopy. These hybrids were assessed in vivo for their antiproliferative activity on MCF-7 breast adenocarcinoma and HT-29 colorectal carcinoma cells, revealing cytotoxicity with IC50 values between 6.0 and 110.5 µM. CBHQ hybrids 5e and 5f displayed enhanced cytotoxicity against both cell lines, whereas CNQ hybrids 6a-c and 6e exhibited higher cytotoxic activity against MCF-7 cells. Docking studies showed strong binding energies (ΔGbin) of CNQs to kinase proteins involved in carcinogenic pathways. Furthermore, our in silico analysis of drug absorption, distribution, metabolism, and excretion (ADME) properties suggests their potential as candidates for cancer pre-clinical assays.

Flexibility in the bridge of chalcone derivatives is important for the inhibition of cellular growth.

Chalcones and their derivatives are a privileged scaffold in medicinal chemistry, demonstrating numerous biological activities. These molecules have shown significant potential toward the development of novel cancer therapies. While much is known about modification to the chalcone aryl rings, little is known about conformations of the bridge between the aryl rings. Here we report the synthesis and biological evaluation of a series of molecules with flexible and rigid bridge conformations. Crystal structures of a select group of molecules were determined. Flexibility in the chalcone bridge containing the enone moiety was determined to be important for activity. Screening in three distinct cancer cell lines showed significant differences in the activity between the flexible and rigid conformations. Crystal structures suggest an increase in bond rotation and weakened π-bonding in the flexible chalcone bridge, which may contribute to the stronger anti-proliferative activity.

Finding a Novel Chalcone-Cinnamic Acid Chimeric Compound with Antiproliferative Activity against MCF-7 Cell Line Using a Free-Wilson Type Approach.

In this work, we carried out the design and synthesis of new chimeric compounds from the natural cytotoxic chalcone 2',4'-dihydroxychalcone (2',4'-DHC, A) in combination with cinnamic acids. For this purpose, a descriptive and predictive quantitative structure-activity relationship (QSAR) model was developed to study the chimeric compounds' anti-cancer activities against human breast cancer MCF-7, relying on the presence or absence of structural motifs in the chalcone structure, like in a Free-Wilson approach. For this, we used 207 chalcone derivatives with a great variety of structural modifications over the α and ß rings, such as halogens (F, Cl, and Br), heterocyclic rings (piperazine, piperidine, pyridine, etc.), and hydroxyl and methoxy groups. The multilinear equation was obtained by the genetic algorithm technique, using logIC50 as a dependent variable and molecular descriptors (constitutional, topological, functional group count, atom-centered fragments, and molecular properties) as independent variables, with acceptable statistical parameter values (R2 = 86.93, Q2LMO = 82.578, Q2BOOT = 80.436, and Q2EXT = 80.226), which supports the predictive ability of the model. Considering the aromatic and planar nature of the chalcone and cinnamic acid cores, a structural-specific QSAR model was developed by incorporating geometrical descriptors into the previous general QSAR model, again, with acceptable parameters (R2 = 85.554, Q2LMO = 80.534, Q2BOOT = 78.186, and Q2EXT = 79.41). Employing this new QSAR model over the natural parent chalcone 2',4'-DHC (A) and the chimeric compound 2'-hydroxy,4'-cinnamate chalcone (B), the predicted cytotoxic activity was achieved with values of 55.95 and 17.86 µM, respectively. Therefore, to corroborate the predicted cytotoxic activity compounds A and B were synthesized by two- and three-step reactions. The structures were confirmed by 1H and 13C NMR and ESI+MS analysis and further evaluated in vitro against HepG2, Hep3B (liver), A-549 (lung), MCF-7 (breast), and CasKi (cervical) human cancer cell lines. The results showed IC50 values of 11.89, 10.27, 56.75, 14.86, and 29.72 µM, respectively, for the chimeric cinnamate chalcone B. Finally, we employed B as a molecular scaffold for the generation of cinnamate candidates (C-K), which incorporated structural motifs that enhance the cytotoxic activity (pyridine ring, halogens, and methoxy groups) according to our QSAR model. ADME/tox in silico analysis showed that the synthesized compounds A and B, as well as the proposed chalcones C and G, are the best candidates with adequate drug-likeness properties. From all these results, we propose B (as a molecular scaffold) and our two QSAR models as reliable tools for the generation of anti-cancer compounds over the MCF-7 cell line.

Fluoroindole chalcone analogues targeting the colchicine binding site of tubulin for colorectal oncotherapy.

Colorectal cancer (CRC) is a common malignancy of the gastrointestinal tract with high morbidity and mortality. Our previous studies have demonstrated that indole-chalcone-based compounds targeting tubulin displayed potential cytotoxicity to CRC cells. Herein, three new series of derivatives were systematically designed and synthesized to explore their structure-activity relationship (SAR) against CRC based on prior research. Among them, a representative fluorine-containing analog (FC116) exerted superior efficacy on HCT116 (IC50 = 4.52 nM) and CT26 (IC50 = 18.69 nM) cell lines, and HCT116-xenograft mice with tumor growth inhibition rate of 65.96% (3 mg/kg). Of note, FC116 could also suppress the growth of organoid models (IC50 = 1.8-2.5 nM) and showed adenoma number inhibition rate of 76.25% at the dose of 3 mg/kg in APCmin/+ mice. In terms of mechanism, FC116 could induce endoplasmic reticulum (ER) stress to produce excess reactive oxygen species (ROS), leading to mitochondrial damage to promote the apoptosis of CRC cells by targeting microtubules. Our results support that indole-chalcone compounds are promising tubulin inhibitors and highlight the potential of FC116 to combat CRC.

Discovery of 4'-trifluoromethylchalcones as novel, potent and selective hCYP1B1 inhibitors without concomitant AhR activation.

Human cytochrome P450 1B1 (hCYP1B1), an extrahepatic cytochrome P450 enzyme over-expressed in various tumors, has been validated as a promising target for preventing and treating cancers. Herein, two series of chalcone derivatives were synthesized to discover potent hCYP1B1 inhibitors without AhR agonist effect. Structure-activity relationship (SAR) studies demonstrated that 4'-trifluoromethyl on the B-ring strongly enhanced the anti-hCYP1B1 effects, identifying A9 as a promising lead compound. Further SAR analysis on A9 derivatives (modified A-ring of 4'-trifluoromethylchalcone) showed that introducing 2-methoxyl improved the anti-hCYP1B1 effect and selectivity, while introducing a methoxyl at the C-4 site was beneficial for avoiding AhR activation. Ultimately, five 4'-trifluoromethyl chalcones were identified as potent hCYP1B1 inhibitors (IC50 < 10 nM), while B18 exhibits the most potent anti-hCYP1B1 effect (IC50 = 3.6 nM), suitable metabolic stability and good cell-permeability. B18 also acted as an AhR antagonist and could down-regulate hCYP1B1 in living systems. Mechanistic studies showed that B18 potently inhibited hCYP1B1 in a competitive inhibition manner (Ki = 3.92 nM), while docking simulations revealed that B18 could tightly bind to the catalytic cavity of hCYP1B1 mainly via hydrophobic and hydrogen-bonding interactions. Furthermore, B18 could potently inhibit hCYP1B1 in living cells and showed remarkable anti-migration ability on MFC-7 cells. Taken together, this study deciphered the SARs of chalcones as hCYP1B1 inhibitors and provided several potent hCYP1B1 inhibitors as promising candidates for the development of more efficacious anti-migration agents.

Anticancer Potential of Natural Chalcones: In Vitro and In Vivo Evidence.

There is no doubt that significant progress has been made in tumor therapy in the past decades. However, the discovery of new molecules with potential antitumor properties still remains one of the most significant challenges in the field of anticancer therapy. Nature, especially plants, is a rich source of phytochemicals with pleiotropic biological activities. Among a plethora of phytochemicals, chalcones, the bioprecursors of flavonoid and isoflavonoids synthesis in higher plants, have attracted attention due to the broad spectrum of biological activities with potential clinical applications. Regarding the antiproliferative and anticancer effects of chalcones, multiple mechanisms of action including cell cycle arrest, induction of different forms of cell death and modulation of various signaling pathways have been documented. This review summarizes current knowledge related to mechanisms of antiproliferative and anticancer effects of natural chalcones in different types of malignancies including breast cancers, cancers of the gastrointestinal tract, lung cancers, renal and bladder cancers, and melanoma.

Novel Tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline Chalcones Suppress Breast Carcinoma through Cell Cycle Arrests and Apoptosis.

Chalcones are interesting anticancer drug candidates which have attracted much interest due to their unique structure and their extensive biological activity. Various functional modifications in chalcones have been reported, along with their pharmacological properties. In the current study, novel chalcone derivatives with the chemical base of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinolin-3-yl)-3-arylprop-2-en-1-one were synthesized, and the structure of their molecules was confirmed through NMR spectroscopy. The antitumor activity of these newly synthesized chalcone derivatives was tested on mouse (Luc-4T1) and human (MDA-MB-231) breast cancer cell lines. The antiproliferative effect was evaluated through SRB screening and the MTT assay after 48 h of treatment at different concentrations. Interestingly, among the tested chalcone derivatives, chalcone analogues with a methoxy group were found to have significant anticancer activity and displayed gradient-dependent inhibition against breast cancer cell proliferation. The anticancer properties of these unique analogues were examined further by cytometric analysis of the cell cycle, quantitative PCR, and the caspases-Glo 3/7 assay. Chalcone methoxy derivatives showed the capability of cell cycle arrest and increased Bax/Bcl2 mRNA ratios as well as caspases 3/7 activity. The molecular docking analysis suggests that these chalcone methoxy derivatives may inhibit anti-apoptotic proteins, particularly cIAP1, BCL2, and EGFRK proteins. In conclusion, our findings confirm that chalcone methoxy derivatives could be considered to be potent drug candidates against breast cancer.

Fatty Acid Conjugated Chalcones as Tubulin Polymerization Inhibitors: Design, Synthesis, QSAR, and Apoptotic and Antiproliferative Activity.

Cancer is often associated with an aberrant increase in tubulin and microtubule activity required for cell migration, invasion, and metastasis. A new series of fatty acid conjugated chalcones have been designed as tubulin polymerization inhibitors and anticancer candidates. These conjugates were designed to harness the beneficial physicochemical properties, ease of synthesis, and tubulin inhibitory activity of two classes of natural components. New lipidated chalcones were synthesized from 4-aminoacetophenone via N-acylation followed by condensation with different aromatic aldehydes. All new compounds showed strong inhibition of tubulin polymerization and antiproliferative activity against breast and lung cancer cell lines (MCF-7 and A549) at low or sub-micromolar concentrations. A significant apoptotic effect was shown using a flow cytometry assay that corresponded to cytotoxicity against cancer cell lines, as indicated by a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. Decanoic acid conjugates were more potent than longer lipid analogues, with the most active being more potent than the reference tubulin inhibitor, combretastatin-A4 and the anticancer drug, doxorubicin. None of the newly synthesized compounds caused any detectable cytotoxicity against the normal cell line (Wi-38) or hemolysis of red blood cells below 100 µM. It is unlikely that the new conjugates described would affect normal cells or interrupt with cell membranes due to their lipidic nature. A quantitative structure-activity relationship analysis was performed to determine the influence of 315 descriptors of the physicochemical properties of the new conjugates on their tubulin inhibitory activity. The obtained model revealed a strong correlation between the tubulin inhibitory activity of the investigated compounds and their dipole moment and degree of reactivity.

Structure optimization of an F-indole-chalcone (FC116) on 4-methoxyphenyl group and therapeutic potential against colorectal cancers with low cytotoxicity.

Advanced metastatic colorectal cancers (CRCs) are regarded as a challenge in clinical cancer therapy. Our previous studies have demonstrated that a representative fluoro-substituted indole-chalcone (FC116), was obtained to display highly potent activity against CRC using multiple in vitro and in vivo mouse models by targeting microtubules. However, several problems, such as low dose tolerance and highly toxic to the brain and colon, low solubility unsuitable for intravenous (i.v.) administration, are still existed and limit further development. Herein, we developed two series of FC116 derivatives on the 4-methoxyphenyl group by a structure-based design strategy. Among them, FC11619 with an amino terminus maintained the in vitro cytotoxicity against HCT-116 CRC in a low nanomolar range. This compound could induce G2/M phase arrest via regulating cyclin B1 expression, produce excess reactive oxygen species (ROS), and target tubulin in CRC cells. In vivo, FC11619 significantly suppressed tumor growth, achieving 65.3 and 73.4 % at doses of 5 and 10 mg/kg/d (i.v., 21 d), which were much better than 54.1% of Taxol at 7 mg/kg. In addition, this compound showed better in vivo tolerance compared to that of FC116 (only 3 mg/kg tolerance, intraperitoneal, i.p.), and no major organ-related toxicity, especially no apparent degenerated neurons, intestinal obstruction in clinical Taxol standard therapy. Taken together, the 4-amino-substitutedphenyl indole-chalcones represent lead compounds as chemotherapy of CRC for further drug development in this field.

Geranylated or prenylated flavonoids from Cajanus volubilis.

Five new flavonoid derivatives, cajavolubones A-E (1-5), along with six known analogues (6-11) were isolated from Cajanus volubilis, and their structures were elucidated by spectroscopic analysis and quantum chemical calculations. Cajavolubones A and B (1 and 2) were identified as two geranylated chalcones. Cajavolubone C (3) was a prenylated flavone, while cajavolubones D and E (4 and 5) were two prenylated isoflavanones. Compounds 3, 8, 9 and 11 displayed cytotoxicity against HCT-116 cancer cell line.